Nanometer-sized devices, such as wire grid polarizers, can be limited in performance by the distance between adjacent features, or the pitch of one feature to the next. For example, for effective polarization of electromagnetic radiation, the pitch in a wire grid polarizer should be less than half the wavelength of the electromagnetic radiation. Wire grid polarizers, with pitch smaller than half the wavelength of visible light, have been demonstrated. See for example U.S. Pat. Nos. 6,208,463; 6,122,103; and 6,243,199. For higher polarization contrast and to allow polarization of smaller wavelengths, such as for polarization of ultra-violet light and x-rays, smaller pitches are needed. Various methods have been proposed to solve this problem. See for example U.S. Pat. No. 7,692,860 and U.S. Publication numbers 2009/0041971 and 2009/0053655.
A desirable feature of wire grid polarizers is to polarize a broad spectrum of electromagnetic radiation with a single polarizer. Wire grid polarizers are typically formed with wires that are the same height. It would be beneficial to form wire grid polarizers with variable wire height in order to allow tuning of the wire grid polarizer for multiple wavelengths and to allow for a smoother Ts curve. Methods have been proposed for wire grid polarizers with different height wires. See for example U.S. Publication numbers 20080037101 and 20080038467.
Wire grid polarizers are typically formed with wires that are situated along a single plane. It would be beneficial to form wire grid polarizers with wires situated at multiple planes. A wire grid polarizer with wires that are situated along multiple planes may be tuned to multiple wavelengths and may allow for a smoother Ts curve. See for example U.S. Publication numbers 20080037101 and 20080038467.
Wire grid polarizers are typically formed with wires that are all comprised of single materials. A wire grid polarizer with some wires comprised one material and other wires comprised of a different material would be beneficial for tuning the wire grid polarizer to multiple wavelengths.